1. Technical Field
The present disclosure relates to a semiconductor structure comprising a high-voltage transistor; voltage dropping means, at least part of which is overlapping the high-voltage transistor; at least one intermediate contact point to the voltage dropping means, connected to at least one intermediate position between a first and a second end of the voltage dropping means.
2. Discussion of the Related Art
In recent years, the requirement for smaller electronic devices has forced manufacturers of such devices to integrate more and more components within printed semiconductor chips.
Additionally, it is common to have high voltages, in the range of 300 to 500 volts, or even higher, on a printed circuit board of such devices.
For instance, in the case of AC/DC power conversion, very complex circuit architecture are required so as to reduce power consumption and achieve high efficiency in order to meet market requests. Accordingly, in such cases, the usage of integrated semiconductor chips guarantees a high level of reliability and a cost effective solution.
However, in some applications, such as Power Factor Corrector, it is necessary to reduce the value of the high voltage, or to generate a low voltage reference correlated with the high voltage value, so as to provide one of the components on the printed circuit board with a lower voltage and proper functionality. Usually, such designs are achieved by placing a resistor divider on the board.
For instance, as can be seen in FIG. 6, a circuit board 6000 includes a first semiconductor chip 6001 and a second semiconductor chip 6002. Both first 6001 and second 6002 semiconductor chips are powered by a high voltage terminal 6003 and are connected to a ground terminal 6004. First semiconductor chip 6001 includes a semiconductor structure 4000 comprising at least one high voltage transistor.
Second semiconductor chip 6002 necessitates a voltage lower than the high voltage potential at high voltage terminal 6003 in order to operate. In order to provide the second semiconductor chip 6002 with such a lower voltage, a resistor bridge is provided on circuit board 6000 by resistors 6005 and 6006.
Such a design is nevertheless expensive since it requires the addition of resistors 6005 and 6006 on the board. Moreover, the presence of the resistors 6005 and 6006 on the board requires a larger board area, which may not always be available in modern electronic devices. Furthermore, the presence of resistors 6005 and 6006 on the board requires additional manufacturing steps, thereby also increasing costs and lowering manufacturing yield.
Thus there is a need in the market for a compact solution to provide intermediate voltage levels from a high voltage available on a printed circuit board.